Sunday

August 2, 2015

August 2, 2015

**Calculus**

What does it mean to span in R2? I have this question: Which of the following sets if vectors span R2? a) {(1,1),(-2,-2)} b) {(1,1),(1,2)} c) {(1,2),(1/2,2)} d) {(-1,1),(1,-1)}
*Wednesday, April 29, 2015 by Sara*

**Calculus**

An airplane is heading due east with an airspeed of 220km/h when it encounters a wind from the south at 76km/h. What is the direction of the resultant velocity of the airplane The answer is E19.06°N but I don't know how
*Wednesday, April 29, 2015 by Sara*

**calculus**

Write and then solve for y = f(x) the differential equation for the statement: "The rate of change of y with respect to x is inversely proportional to y^4."
*Wednesday, April 29, 2015 by Anonymous*

**Calculus-limits**

What is the limit as x approaches a of (sinx-sin a)/(x-a)? a. -sin a b. cos a c. -sin x d. cos x e. undefined Thanks!
*Wednesday, April 29, 2015 by ashley*

**calculus**

For the function f(x)=x^3e^x, determine intervals of increase and decrease and the absolute minimum value of f(x) To do this I found the derivative which is f'(x)=3x^2e^x. Then I set it to zero: f'(x)=0 0=3x^2e^x How would I isolate x? And when I do, I would sub that x...
*Wednesday, April 29, 2015 by Sara*

**Calculus-limits**

I'm studying for the AP exam and I can't figure this problem out. I thought the answer was negative infinity but that isn't an option. Thank you in advance! What is the limit as x approaches infinity of (9x-x^2-7x^4)/(x^3+12x)? a. 9 b. 7 c. -7/12 d. -7 e. Does not ...
*Wednesday, April 29, 2015 by ashley*

**Calculus**

Can you please explain how I would solve these questions? 1) Which point is 2 units from the line 12x-9y-5=0? a)(8,3) b)(7/6, -7/3) c)(14,6) d)(1,1) 2.) Which of the following sets of vectors spans R2: a) {(1,1),(-2,-2)} b) {(1,1),(1,2)} c) {(1,2),(1/2,2)} d) {(-1,1),(1,-1)}
*Wednesday, April 29, 2015 by Sara*

**calculus**

1.Solve the differential equation dy/dx= y^2/x^3 for y=f(x) with the condition y(1) = 1. 2.Solve the differential equation y prime equals the product of 2 times x and the square root of the quantity 1 minus y squared. Explain why the initial value problem y prime equals the ...
*Tuesday, April 28, 2015 by Anonymous*

**Pre-Calculus**

Explain the difference between sin^-1(x) and 1/sin(x), Are there different expressions for both these functions?
*Tuesday, April 28, 2015 by Andrea*

**Pre-Calculus**

At 34 degrees north latitude, the longest day of the year has 14.273 hours of daylight, and the shortest day 9.726 hours. If the equinox falls on march 21(day 80), model the hours of the daylight by day?
*Tuesday, April 28, 2015 by Jessica*

**Pre-Calculus**

f(x) is a sinusoidal curve with maximum at f(0)=10 and next minimum at f(6)=0. Find the equation?
*Tuesday, April 28, 2015 by Richard*

**Calculus**

Piecewise function problem. Let f(x)={ax^2+1/3, x is greater than or equal to 1; bx-10/3, x<1. If the function is differentiable, find the sum of a+b.
*Tuesday, April 28, 2015 by Anonymous*

**Calculus**

The rate of change of atmospheric pressure P with respect to the altitude h is proportional to P provided that the temperature is consistent. At 15 degrees Celsius, the pressure is 101.3 pounds per square inch (psi) at sea level and 87.1 psi at height 1000m. Find the pressure ...
*Tuesday, April 28, 2015 by Anonymous*

**Calculus**

Susan pulls on a rope sleigh with a force of 120 N. If the rope makes an angle of 25 degrees with the horizontal, what is the force that tends to lift the sleigh? a)120.00 N b)108.76 N c)50.71 N d)84.85 N how would you know?
*Tuesday, April 28, 2015 by Sara*

**Calculus**

Can someone check my work on this problem? I'm studying for the AP test and I would really appreciate any help. Let f(x) = the definite integral from [-2,(x^2-3x)] of e^(t^2) dt At what value of x is f(x) a minimum? a. For no value of x b. 1/2 c. 3/2 d. 2 e. 3 The answer I...
*Tuesday, April 28, 2015 by ashley*

**Calculus**

Find the area of the largest rectangle that fits inside a semicircle of radius 10 (one side of the rectangle is along the diameter of the semicircle).
*Tuesday, April 28, 2015 by Chris*

**Calculus help??**

I'm not sure how to solve this and help would be great! d/dx [definite integral from 0 to x of (2pi*u) du] is: a. 0 b. 1/2pi sin x c. sin(2pi x) d. cos (2pi x) e. 2pi cos (2pi x) This is the fundamental theorem, right? What's confusing me is the u and du and the end. ...
*Tuesday, April 28, 2015 by ashley*

**Calculus I**

Marketing tells you that if you set the price of an item at $10 then you will be unable to sell it, but that you can sell 500 items for each dollar below $10 that you set the price. Suppose your fixed costs total $3000, and your marginal cost is $2 per item. What is the most ...
*Tuesday, April 28, 2015 by John*

**Differential Calculus**

a person standing at the edge of a cliff throws a rock directly upward. it observed that 2 seconds later, the rock is it maximum height and that 5 seconds after it reached the highest point, it hits the ground at the base of the cliff. what is the initial velocity of the rock
*Tuesday, April 28, 2015 by rex*

**Calculus**

find the area of the region bounded by the curves y=x^2-1 and y =cos(x)
*Monday, April 27, 2015 by joe9*

**Calculus**

find area of the region bounded by the curves y=x^2-1 and y=cos(x). give your answer correct to 2 decimal places.
*Monday, April 27, 2015 by joe9*

**Calculus**

How would I find the second derivative if f(x)= √(x^3+2) using the quotient rule. I got to the step where [(12x√(x^3+2))-(9x^4/√(x^3+2))]/4(x^3+2) how would i go from that to: (3x(x^3+8))/(4(x^3+2)^3/2)
*Monday, April 27, 2015 by Sara*

**calculus check**

Find the limit as x approaches 3 of [(2x^3-5x^2+7)/(3sin(xpi/6)-cos(xpi))] When I plugged in 3, I got 4.
*Sunday, April 26, 2015 by Jeff*

**calculus**

Given the relationship 2x^2 + y^3 =10, with y > 0 and dy, dt = 3 units/min., find the value of dx, dt at the instant x = 1 unit.
*Sunday, April 26, 2015 by Anonymous*

**Calculus 2**

Determine whether the series is convergent, absolutely convergent, conditionally convergent, or divergent. On top of the summation sign (∑) is infinity. Under the summation sign is n=2, and right next to it (to the right of ∑ sign) is (n root of (n)-1)^n (Sorry I ...
*Sunday, April 26, 2015 by Sena*

**Calculus**

Find the average value of f(x) on the interval [-1, 3] when f'(x)=3x^2-6x and f(2)=0.
*Sunday, April 26, 2015 by Anonymous*

**Calculus**

The expression dy/dx = x*(cube root y) gives the slope at any point of the graph of the function f(x) where f(2) = 8. A. Write the equation of the tangent line to f(x) and any point (2,8). B. Write an expression for f(x) in terms of x. C. What is the domain of f(x)? D. What is...
*Sunday, April 26, 2015 by ashley*

**Calculus**

Find limit as x approaches 0 [7x/(sqrt(x+4)-2)]
*Sunday, April 26, 2015 by Anonymous*

**Calculus**

People are entering a zoo at the rate of 100e^t+75t people per hour where t is the amount of time the zoo has been open on that day measured in hours. If the doors are open at 9:00 AM, how many hundreds of people have entered the zoo at 11:40 AM? (Nearest integer)
*Sunday, April 26, 2015 by Sarah*

**calculus**

If f(x)=the integral of (3x^2+2x+4) dx, find C if f(1)=10.
*Sunday, April 26, 2015 by Jeff*

**Calculus**

Find the area bounded by y=x^2-4x+3 and y=x+4 to the newrest integer.
*Sunday, April 26, 2015 by Anonymous*

**Calculus 2**

Use the Comparison Test to determine whether the series is convergent or divergent. On top of the summation sign (∑) is infinity. Under the summation sign is n=1, and right next to it (to the right of ∑ sign) is cos^2n/n^2. How would I compare them and come to the ...
*Saturday, April 25, 2015 by Sena*

**calculus**

A water tank has the shape of an inverted right circular cone with base radius 3 meters and height 6 meters. Water is being pumped into the tank at the rate of 12 meters3/sec. Find the rate, in meters/sec, at which the water level is rising when the water is 2 meters deep. ...
*Saturday, April 25, 2015 by ana*

**Calculus 2**

Determine whether the p-series is convergent or divergent. On top of the summation sign (∑) is infinity. Under the summation sign is n=1, and right next to it (to the right of ∑ sign) is 3/n^e. I was wondering how would you start the problem from start to finish. ...
*Saturday, April 25, 2015 by Sena*

**Pre-Calculus**

Two hoses together fill a pool in 2 h. If only hose A is used, the pool fills in 3 h. How long would it take to fill the pool if only hose B were used? I multiplied 3 and 2 and got 6 hours. Is this a valid method? Thanks
*Saturday, April 25, 2015 by Lucina*

**Calculus**

A circle has a radius lf 10/(pi-1) which is the same value as the side of a square. Both the radius of the circle and the side of the square are gowing at 1 in/sec. Find the difference between the rates of change of their area in in/sec.
*Saturday, April 25, 2015 by Sarah*

**Calculus**

Given f(x)=x^2-27x-28, find the largest integer in shich f is decreasing.
*Saturday, April 25, 2015 by Anonymous*

**Calculus**

A particle moves along the curve y = 3x2 + 1 in such a way that the y value is increasing at the rate of 3 units per second. At what rate is x changing when x = 2?
*Saturday, April 25, 2015 by emma *

**Calc 1**

Consider the following function. f(x) = x^6 ln x (a) Use l'Hospital's Rule to determine the limit as x → 0+. (b) Use calculus to find the minimum value. Find the interval where the function is concave up. (Enter your answer in interval notation.) Find the ...
*Friday, April 24, 2015 by TayB*

**calculus**

Sketch the region enclosed by the given curves. Decide whether to integrate with respect to x or y. Then find the area of the region. 2y=3 sqrt x,y=3 and 2y+1x=4
*Friday, April 24, 2015 by webworks*

**Pre-Calculus**

Simplify the rational expression and then add or subtract. Express answers in simplest form and identify all non-permissible values. (The non-permissible value is not the issue. It is the simplification) 3x + 15/x^2-25 + 4x^2 -1/ 2x^2 + 9x -5 3(x+5)/(x+5)(x-5) + 4x^2 -1/ (x+5...
*Wednesday, April 22, 2015 by Lucina*

**Calculus Indefinite Intergral**

I need help with integrating these two problems. Im stuck. 1. integrate (sin^-1)dx/((1-x^2)^3/2) sin^-1 aka arcsin 2. integrate dx/((1-x^2)^3/2) by using 1/z Any and all help will be appreciated!
*Wednesday, April 22, 2015 by John*

**Calculus**

(Bees collecting pollen and nectar - Optimization) Many bees collect both pollen and nectar. Pollen is used for protein, and nectar is used for energy. Suppose the amount of nectar harvested during t seconds on a flower is: F(t)=t/(1+t) and that the amount of pollen harvested ...
*Wednesday, April 22, 2015 by Corbin*

**pre-calculus**

eliminate parameters of x=1+cos t y=1-sin t graph the parametric equations
*Wednesday, April 22, 2015 by JK*

**calculus**

In the space below, provide the smaller of the two positive integers that add to 40 and have the largest possible product
*Wednesday, April 22, 2015 by emma *

**calculus**

If 800 feet of fencing is used to enclose a rectangular plot of land that borders a river, what is the maximum area that can be enclosed? Answer to the nearest square foot without commas. For example, if the answer is 1,000, write 1000.
*Wednesday, April 22, 2015 by emma *

**calculus (please help)**

find the volume of the solid whose bounded by the circle x^2+y^2=4 and whose cross sections perpendicular to the y-axis are isosceles right triangles with one leg in the base. Please give explanation and steps
*Wednesday, April 22, 2015 by may*

**Pre-Calculus**

Can the following be reduced any further? 14x^2/56y^3 I did not reduce because there were different variables in the numerator and denominator. Thanks
*Wednesday, April 22, 2015 by Lucina*

**calculus**

find the area under the curve y= 1/(3x+1)^2 over the interval [0,1]. please show all steps
*Wednesday, April 22, 2015 by Linda*

**Calculus**

F(x)=Integral of (-12sinx/cos^2x) dx+c F(0)=4. Find C
*Wednesday, April 22, 2015 by Anonymous*

**integral calculus**

Integrate with respect to x : ∫3−1x7+x2−−ͨ2;−−√dx
*Wednesday, April 22, 2015 by yomi*

**calculus**

A firework is launched at the rate of 10 feet per second from a point on the ground 50 feet from an observer. To 2 decimal places in radians per second, find the rate of change of the angle of elevation when the firework is 40 feet above the ground. Type your answer in the ...
*Monday, April 20, 2015 by emma *

**Calculus**

A fence 4 feet tall runs parallel to a tall building at a distance of 2 feet from the building. What is the length of the shortest ladder that will reach from the ground over the fence to the wall of the building?
*Monday, April 20, 2015 by Anonymous*

**math**

Use Part 1 of the Fundamental Theorem of Calculus to find the derivative of the function. g(x) = e^(3t^2) − 3t dt from 4 to x
*Monday, April 20, 2015 by jessica*

**Calculus**

Consider the function f : [-pi,pi] --> R given by f(x) = e^-x*sin(x). (a) Calculate local maxima/minima and points of in ection of f(x).
*Monday, April 20, 2015 by Galagan*

**Calculus check and help**

Let f and g be the functions given by f(x)=1+sin(2x) and g(x)=e^(x/2). Let R be the shaded region in the first quadrant enclosed by the graphs of f and g. A. Find the the area of R. B. Find the value of z so that x=z cuts the solid R into two parts with equal area. C. Find the...
*Sunday, April 19, 2015 by Anonymous*

**Calculus**

Evaluate the integral f sin(x)/1-sin^2(x) dx
*Sunday, April 19, 2015 by joe9*

**Calculus**

Let f and g be the functions given by f(x)=1+sin(2x) and g(x)=e^(x/2). Let R be the shaded region in the first quadrant enclosed by the graphs of f and g. A. The region R is the base of a solid. For this solid, the cross sections, perpendicular to the spx-axis, are rectangles ...
*Sunday, April 19, 2015 by Anonymous*

**Calculus**

Determine the interval on which f(x) = sqrt x-3 is integrable
*Sunday, April 19, 2015 by joe9*

**Calculus**

Give a Right-hand sum approximation of integral 1 to 4 of x^2 with n=4? I have done this problem alot and my teacher says the answer is 30 but I cant get it. HELP
*Sunday, April 19, 2015 by Jason*

**Calculus**

Let f and g be the functions given by f(x)=1+sin(2x) and g(x)=e^(x/2). Let R be the shaded region in the first quadrant enclosed by the graphs of f and g. A. Find the volume of the solid generated when R is revolved around the line y=pi. B. Fine the volume of the solid ...
*Sunday, April 19, 2015 by Anonymous*

**Pre-Calculus**

A sailboat in a lake travels 4 km due north and then 4 km due west. From there, the boat travels 5 km due north and 4 km due west. How far is the bboat from the starting point? Express your answer as a mixed radical. (How would I use radicals for this??) Thanks!
*Sunday, April 19, 2015 by Lucina*

**Calculus**

Let f and g be the functions given by f(x)=1+sin(2x) and g(x)=e^(x/2). Let R be the shaded region in the first quadrant enclosed by the graphs of f and g. A. Find the the area of R. B. Find the value of z so that x=z cuts the solid R into two parts with equal area. C. Find the...
*Sunday, April 19, 2015 by Anonymous*

**Calculus**

Write the Riemann sum to find the area under the graph of the function f(x) = x4 from x = 5 to x = 7.
*Saturday, April 18, 2015 by joe9*

**PRE - CALCULUS**

A woman works out by running and swimming. When she runs, she burns 7 calories per minute. When she swims, she burns 8 calories per minute. She wants to burn at least 336 calories in her workout. Write an inequality that describes the situation. Let x represent the number of ...
*Friday, April 17, 2015 by Ciara*

**PRE - CALCULUS**

Use Gaussian elimination to find the complete solution to the system of equations, or state that none exists. Show your work. 4x-y+3z = 12 x+4y+6z =-32 5x+3y+9z = 20 ...... I NEED HELP WITH THE OTHER TWO PLEASE :) 4 -1 3 | 12
1 4 6 | -32
5 3 9 | 20 1 0 0
...
*Friday, April 17, 2015 by Ciara*

**PRE - CALCULUS**

A statement Sn about the positive integers is given. Write statements Sk and Sk+1, simplifying Sk+1 completely. Sn: 1 + 4 + 7 + . . . + (3n - 2) = n(3n - 1)/2
*Friday, April 17, 2015 by Ciara*

**PRE - CALCULUS**

A statement Sn about the positive integers is given. Write statements S1, S2, and S3, and show that each of these statements is true. Show your work. Sn: 2+5+8+...+(3n-1)=n(1+3n)/2
*Friday, April 17, 2015 by Ciara*

**Calculus**

A Norman window has the shape of a semicircle atop a rectangle so that the diameter of the semicircle is equal to the width of the rectangle. What is the area of the largest possible Norman window with a perimeter of 31 feet? A = x(31/2-1/4 (2+pi) x)+.5pi(x/2)^2 This is what I...
*Friday, April 17, 2015 by Ryan kustin*

**physics**

Answer the following question:Be sure to show all work. Include formulae and units.Be sure to include relavant, meaningful diagram and a complete circuit diagram with circuit related problem. take enough space, don't try to squeeze everything on a small space!(problems are...
*Friday, April 17, 2015 by titu*

**Ap Calculus **

Find the following volumes formed by rotating the region bounded by: y=x^2, x^2+y^2=-2 (set up using shell method)
*Thursday, April 16, 2015 by Kaylea *

**Ap Calculus**

How do I find the following volumes formed by rotating the region bounded by: y=x^2, x^2+y^2=2, about the line y=-2(set up only using dish or washer method)
*Thursday, April 16, 2015 by Kaylea *

**Calculus check and help**

Let R be the region bounded by the curves y=lnx^2 and y=x^2-4 to the right of the y-axis. A. Find the area of R. B. Find the folume geneated when R is rotated about the line y=-4. C. Write, but do not evaluate the integral expression that gives the volume of the solid ...
*Thursday, April 16, 2015 by Anonymous*

**Calculus check**

The functions f and g are given by f(x)=sqrt(x^3) and g(x)=16-2x. Let R be the region bounded by the x-axis and the graphs of f and g. A. Find the area of R. B. The region R from x=0 to x=4 is rotated about the line x=4. Write, but do not evaluate, an integral expression the ...
*Thursday, April 16, 2015 by Anonymous*

**calculus word prob**

Two buildings at opposite corners of a parking lot need to be connected by cable that will be buried under ground. It costs $11/ft to lay accross parking lot and $8/ft to lay along the sides. The lot is 300ft by 360 ft rect from pt A to the opposite corner with indents of 60ft...
*Thursday, April 16, 2015 by Anonymous*

**calculus**

Set up, but do not evaluate, the integral which gives the volume when the region bounded by the curves y = Ln(x), y = 1, and x = 1 is revolved around the line y = −3.
*Thursday, April 16, 2015 by Anonymous*

**calculus**

The base of a solid in the xy-plane is the first-quadrant region bounded y = x and y = x2. Cross sections of the solid perpendicular to the x-axis are equilateral triangles. What is the volume, in cubic units, of the solid?
*Thursday, April 16, 2015 by Anonymous*

**calculus**

Determine if the Mean Value Theorem for Integrals applies to the function f(x) = x^3 − 9x on the interval [−1, 1]. If so, find the x-coordinates of the point(s) guaranteed to exist by the theorem
*Thursday, April 16, 2015 by Anonymous*

**calculus**

An object has a constant acceleration of 40 ft/sec^2, an initial velocity of −20 ft/sec, and an initial position of 10 ft. Find the position function, s(t), describing the motion of the object.
*Thursday, April 16, 2015 by Anonymous*

**pre - CALCULUS**

Solve the system of equations using matrices. Use Gaussian elimination with back- substitution. x+y+z = -5 x-y+3z = -1 4x+y+z = -2
*Wednesday, April 15, 2015 by Ciara*

**pre - CALCULUS**

Use Gaussian elimination to find the complete solution to the system of equations, or state that none exists. Show your work. 4x-y+3z = 12 x+4y+6z =-32 5x+3y+9z = 20
*Wednesday, April 15, 2015 by Ciara*

**pre - CALCULUS**

Use Gaussian elimination to find the complete solution to the system of equations, or state that none exists. Show your work. 4x-y+3z = 12 x+4y+6z =-32 5x+3y+9z = 20
*Wednesday, April 15, 2015 by Ciara*

**calculus (please help. URGENT!)**

A hemispherical tank with a radius of 10m is filled from an input pipe at a rate of 3m^3/min. How fast is the water level rising when the water level is 5m from the bottom of the tank? (hint: the volume of the cap of thickness of h sliced from a sphere of radius r is pih^2(3r-...
*Wednesday, April 15, 2015 by Linda*

**calculus**

A hemispherical tank with a radius of 10m is filled from an input pipe at a rate of 3m^3/min. How fast is the water level rising when the water level is 5m from the bottom of the tank? (hint: the volume of the cap of thickness of h sliced from a sphere of radius r is pih^2(3r-...
*Wednesday, April 15, 2015 by Linda*

**calculus (optimization prob help!)**

Imagine a flat-bottomed cylinderal container with a circular cross section of radius 4 in. a marble with radius 0<r<4 inches is placed in the bottom of the can. what is the radius of the bottom that requires the most water to cover it. (include first or second derivative...
*Wednesday, April 15, 2015 by Linda*

**calculus (steps and explanation plz)**

Find a curve y=f(x) with the following properties (i) y"=6x and (ii) its graph passes through the point (1,1) and has a horizontal tangent there.
*Wednesday, April 15, 2015 by Linda*

**pre - CALCULUS**

Use Gaussian elimination to find the complete solution to the system of equations, or state that none exists. Show your work. 4x-y+3z = 12 x+4y+6z =-32 5x+3y+9z = 20
*Wednesday, April 15, 2015 by Ciara*

**Pre - CALCULUS**

Graph the function. Then use your graph to find the indicated limit. You do not have to provide the graph f(x) = 5x - 3,lim x -->5 f(x)
*Wednesday, April 15, 2015 by Ciara*

**calculus**

3:For an object whose velocity in ft/sec is given by v(t) = −2t^2 + 4, what is its distance travelled, in feet, on the interval t = 0 to t = 2 secs? a:4.876 b:2.667 c:9.752 d:2.438
*Tuesday, April 14, 2015 by Anonymous*

**calculus multiple choice**

1.The region in the first quadrant bounded by the x-axis, the line x = ln(π), and the curve y = sin(e^x) is rotated about the x-axis. What is the volume of the generated solid? a: 0.906 b:0.795 c:2.846 d: 2.498 2.Find the average value of f(x)=2/x over the interval [1, 3...
*Tuesday, April 14, 2015 by Anonymous*

**PRE - CALCULUS**

Graph the function. Then use your graph to find the indicated limit. You do not have to provide the graph f(x) = 5x - 3,lim x -->5 f(x)
*Tuesday, April 14, 2015 by Ciara*

**Calculus**

We can find some of the solutions of sin x = 0.2 graphically by graphing y = sin x and y = 0.2 (I was able to figure this one out) Use the graph below to estimate some of the solutions. (Let −3π < x < 3π.) Enter your answers as a comma-separated list. ...
*Tuesday, April 14, 2015 by Angela*

**Pre - CALCULUS**

Graph the function. Then use your graph to find the indicated limit. You do not have to provide the graph f(x) = 5x - 3,lim x -->5 f(x)
*Tuesday, April 14, 2015 by Ciara*

**Pre-Calculus (Check)**

Please tell me what I'm doing wrong... The side lengths of tops of three squares tables can be described as three consecutive integers. The combined area of the table tops is 677 sq in. Algebraically, determine the roots of the quadratic equation. (I'll use quadratic, ...
*Tuesday, April 14, 2015 by Lucina*

**Calculus **

A rectangular page is to have a print area of 96 square inches. The top and bottom margins are to be 1.5 inches each and the left and right margins are to be 1 inch each. What dimensions will minimize the total area of the page. I got L=8sqr(2) But I'm not sure how to get...
*Monday, April 13, 2015 by Terry*

**calculus**

A 15-ft ladder rests against a vertical wall. If the top of the ladder slides down the wall at a rate of 0.33 ft/sec, how fast, in ft/sec, is the bottom of the ladder sliding away from the wall, at the instant when the bottom of the ladder is 9 ft from the wall? Answer with 2 ...
*Monday, April 13, 2015 by emma *

**Calculus**

a) The value of a computer after t years after purchase is v(t) = 1000e^(-0.45t). At what rate is the computer's value falling after 5 years? b) Assume that the total revenue received from the sale of x items is given by R(x) = 32 ln (5x+3), while the total cost to produce...
*Monday, April 13, 2015 by Jack*

**calculus**

The area A = πr2 of a circular water ripple changes with the radius. At what rate does the area change with respect to the radius when r = 4ft?
*Monday, April 13, 2015 by emma *

**Pre-Calculus**

The equation H(t) = 30 + 24t - 6t^2 describes the height of a ball at any time t. What's the height of the ball after two seconds h = 30 + 24(2) + 6(2)^2 h = 30 + 48 -24 h = 54 units Therefore, the maximum height is 54 units
*Monday, April 13, 2015 by Lucina*

**calculus**

The height of a cylinder with a fixed radius of 4 cm is increasing at the rate of 2 cm/min. Find the rate of change of the volume of the cylinder (with respect to time) when the height is 14cm.
*Monday, April 13, 2015 by emma *